AGPtek Refrigerant Halogen Freon Leak Detector CFC HFC HCFC Air Gas HVAC Tool 100% Brand new Halogen Gas HFC CFC Refrigerant Leak Detector Checker. Protect the environment and check for potentially harmful halogen leaks with this portable, handheld leak checker. Detects all HFC (134a) CFC refrigerants. Highly precise for accurate readings time after time,Flexible probe allows you to reach into awkward corners and tight spaces. Audio 'siren' and visual LED light alert when leak is found.